The Bell System Technical Journal 



Vol. XXIX July, 1950 No. j 



Copyright, 1950, American Telephone and Telegraph Company 



Principles and Applications of Waveguide Transmission 



By GEORGE C. SOUTHWORTH 



Copyright, 1950, D. \'an Nostrand Company, Inc. 



Under the aliove title, D. Van Nostrand Company, Inc. will shortiv publish 

 the book from which the following article is e.xcerpted. Dr. Southworth is one 

 of the leading authorities on waveguides and was one of the lirst to foresee the 

 great usefulness that this form of transmission might offer. The editors of the 

 Bell System Technical Journal are grateful for permission to ])ublish here parts 

 of the preface and the historical introduction and chapter 6 in its entirety. 



Preface 



Though it has been scarcely fifteen years since the waveguide was pro- 

 posed as a practicable medium of transmission, rather important applica- 

 tions have already been made. The first, which was initiated several years 

 ago, was in connection with radar. A more recent and possibly more im- 

 portant application has been in television where waveguide methods pro- 

 vide a very special kind of radio for relaying program material cross-country 

 from one tower top to another. Already Boston and New York have been 

 connected by this means and shortly Chicago and intervening cities will 

 be added. Other networks extending as far west as the Pacific may be ex- 

 pected. It is reasonable to e.xpect that these two apj)lications will be but 

 the beginning of a more general use. 



Interest in the subject of waveguide transmission is not limited to com- 

 mercial application alone. A comparable interest, perhaps less readily evalu- 

 ated but nevertheless extremely important, lies in its usefulness in teaching 

 important physical principles. For example there are many concepts that 

 follow from the electromagnetic theory that, in their native mathematical 

 form, may appear rather abstract. However, when translated to phenomena 

 actually observed in waveguides, they become very real indeed. As a re- 

 sult, these new techniques have already assumed a place of considerable 

 importance in the teaching of electrical engineering and applied physics both 

 in lecture demonstrations and in laboratory exercises. It is to be expected 



295 



